Photos can take up a significant amount of storage space on an external hard drive. The amount of storage needed depends on several factors, including:
Resolution of the photos
Higher resolution photos take up more storage space because they contain more pixel data. Common photo resolutions include:
- Low resolution – Under 1 megapixel (MP)
- Medium resolution – 1-3 MP
- High resolution – 4-6 MP
- Very high resolution – Over 6 MP
As a general guideline:
- Low resolution photos are under 1 megabyte (MB) in size
- Medium resolution photos are 1-3 MB
- High resolution photos are around 4-6 MB
- Very high resolution photos are over 6 MB
So higher resolution photos take up more space. A 10 megapixel photo will be around 2-3 times larger than a 5 megapixel photo of the same scene.
File format of photos
The most common photo file formats are:
- JPEG – Uses lossy compression, file sizes vary.
- PNG – Lossless compression, larger file sizes.
- RAW – No compression, very large file sizes.
- TIFF – Lossless or lossy compression, file sizes vary.
RAW files take up the most space because they contain untouched image data direct from the camera sensor. JPEGs are typically much smaller because they use lossy compression which removes some image data.
As a rough guide, a 10 MP JPEG photo is around 2-4 MB, while a 10 MP RAW photo from the same camera could be around 10-20 MB.
Number of photos
The more photos you store, the more space you will need. Even small 1-2 MB JPEGs will quickly add up if you have thousands of them. Storing a large photo library will require a higher capacity hard drive.
If storing video files as well as photos, this will also increase the storage space required. Video files are much larger than photos due to the large amount of data needed to store moving images.
Some typical video file sizes are:
- 720p video – Around 500 MB per minute
- 1080p video – Around 1 GB per minute
- 4K video – Around 5 GB per minute
So just a few 4K videos can easily take up terabytes of space.
Hard drive capacity needed
As a rough guide for photo storage requirements:
- A few hundred medium resolution JPEGs – 250 GB hard drive
- A few thousand high resolution photos – 500 GB to 1 TB
- A large collection of over 10,000 photos – 2 TB or more
- RAW files or videos – Will require more storage, 3 TB or higher
However the actual capacity needed depends entirely on your specific photo and video collection. The only way to accurately determine the size is to:
- Take inventory of all the files you want to store – quantity and file types.
- Calculate total estimated file sizes based on resolutions and durations.
- Choose a hard drive that meets or exceeds the estimated total capacity.
It’s a good idea to allow some extra room for future growth of your library. You can use a tool such as Photolab’s hard drive calculator to estimate capacity based on your photo collection details.
Factors reducing photo file sizes
There are some ways you can reduce the storage space photos take up:
- Store JPEGs instead of RAWs – JPEGs are smaller due to compression.
- Use lower resolution settings on your camera.
- Use higher JPEG compression ratios for smaller files.
- Delete unwanted photos to reduce the number stored.
- Use photo optimization software to reduce file sizes.
However, higher compression or resolution means lower photo quality. There is a trade-off between file size and quality.
External hard drive types
Photos and videos can be stored on different types of external drives:
- HDD (hard disk drive) – Cheapest per TB, range from portable drives to desktop RAID setups.
- SSD (solid state drive) – More expensive, faster, more portable, and more durable.
- Hybrid drives – HDD with a small SSD cache to improve performance.
- RAID arrays – Multiple HDDs for speed and/or redundancy.
SSDs are great for working directly with photos and videos due to their speed. But HDDs offer the lowest cost per terabyte for maximize storage capacity.
Photo storage strategy tips
To effectively store a large photo library on an external drive, follow these tips:
- Use a high capacity HDD – At least 2 TB or larger to allow for growth.
- Use multiple drives – Store photos across 2+ drives for redundancy.
- Backup originals – Keep original high-res photo and video masters.
- Store edits separately – Save edited versions separately from original files.
- Use cloud backup – Also back up your library to the cloud.
- Catalog and organize – Use photo organizing software and maintain a catalog.
- Format properly – Use a filesystem optimized for large media like exFAT.
- Work from a copy – Store working files separately from the master library.
Following best practices for photo library management will ensure your irreplaceable photos and videos remain safe and accessible on external drives.
Photos and videos can easily consume terabytes of hard drive space. The exact amount depends on factors like resolution, quantity, file formats, and videos. As a general guideline, several thousand high resolution photos will require at least 500GB to 1TB of capacity.
To store large photo libraries, external hard drives are a great option thanks to their storage capacities and portability. Just be sure to use sufficiently large drives, back up to multiple locations, and manage your library effectively. With some planning, external drives can provide reliable long term storage for all your precious photographic memories.